1. Field of the Invention
This invention relates to performance operator control apparatuses for controlling various types of apparatuses equipped with performance operators, such as keyboard instruments (e.g., player pianos), which allow users to generate acoustic sounds by depressing keys for striking strings, which allow users to record musical tone data such as MIDI (i.e., Musical Instrument Digital Interface) data, and which are capable of playing automatic performance using acoustic sounds by driving keys based on musical tone data, and multidimensional performance control apparatuses (e.g., music playing devices and game playing devices), which are equipped with performance operators for performing drive controls on musical performance and which are equipped with other types of operators such as joysticks for performing drive controls on musical performance in a multidimensional manner.
This application claims priority on Japanese Patent Applications Nos. 2003-419311, 2003-419312, and 2004-4569, the contents of which are incorporated herein by reference.
2. Description of the Related Art
Conventionally, player pianos (or automatic performance pianos) are each designed to simulate acoustic pianos in which key motions are transmitted to hammers via action mechanisms so that strings are struck by hammers to produce acoustic sounds, wherein they are equipped with solenoids for electronically driving keys and operator I/O control units for controlling electrification with regard to solenoids. For example, when keys are driven using solenoids, an operator I/O control unit turns on or off transistors by drive signals (e.g., PWM signals, namely, pulse-width modulated signals), so that the solenoids are supplied with drive currents (or PWM currents) via transistors. They can be also equipped with feedback controls for driving keys. Japanese Patent Application Publication No. H05-152127 discloses a solenoid abnormality detection circuit for detecting abnormal operation of a solenoid, which upon detection of a short-circuit event (or a semi-short-circuit event) of a transistor, prevents an abnormal current from being supplied to the solenoid, wherein a control circuit inhibits electrification from being applied to the solenoid in response to an abnormality detection signal. In addition, Japanese Patent Application Publication No. H10-177378 discloses a key-touch response control apparatus (or a key-touch sensation control apparatus) that controls reactions of keys when they are depressed and that drives keys (or other performance operators) to play a musical performance.
The aforementioned solenoid abnormality detection circuit may require specific lines for transmitting signals representing the abnormality to the control circuit to inhibit electrification from being applied to the solenoid. This unnecessarily increases the overall area of a circuit board and the total number of lines adapted to a keyboard. Similar problems may occur due to the necessity of the ‘specifically designed’ control circuit. This problem occurs not only in the solenoid abnormality detection circuit detecting the abnormality but in the other circuitry using the configuration for detecting internal monitoring signals, for example, in the circuitry for detecting the temperature of a circuit board of a keyboard so as to output a temperature detection signal to a control circuit and the like.
In addition, the solenoid abnormality detection circuit must be designed such that the abnormality content can be easily determined in order to conduct maintenance for coping with the abnormality. It may be possible to display some message when the control circuit receives an abnormality detection signal, wherein the control circuit must be designed to output signals representing the abnormality to a display circuit and the like. This may require specific lines for transmitting signals representing the abnormality, which in turn unnecessarily increases the overall area of a circuit board and the number of lines adapted to a keyboard. Similar problems may occur due to the necessity of the ‘specifically designed’ control circuit. Normally, it is convenient for users that while an automatic performance is in progress, the temperature control is performed to monitor the temperature of a circuit board of a keyboard, thus notifying users of the occurrence of the temperature abnormality. In addition, it is convenient for users to confirm the occurrence of sensor signals being output from key sensors, hammer sensors, and pedal sensors during the automated drive of keys and/or pedals being automatically operated based on performance data or during the manual drive of keys and/or pedals being manually operated by the player. This also requires specific lines for transmitting signals representing the sensor output, which in turn unnecessarily increases the overall area of a circuit board and the number of lines adapted to the keyboard. That is, the aforementioned modification adapted to the conventional technology causes complication in circuit configurations, which in turn increases the probability that an error may occur in a certain part of the circuitry, whereby it becomes very difficult to precisely notify users of the occurrence of the abnormality.
In addition, the aforementioned operator I/O control unit is constituted by a plurality of integrated circuits (or ICs) having numerous output ports, which output drive signals for driving the prescribed number of keys, and numerous input ports, which input feedback signals regarding servo controls from velocity sensors of solenoids. It may be necessary to perform inspection as to whether or not ICs operate normally; however, the provision of a ‘specifically designed’ inspection circuit increases the overall area of a circuit board and the number of lines adapted to a keyboard.